This invention relates to a monoclonal antibody, more especially a monoclonal antibody specific for certain cancers. Also, it relates to a new method which can be utlized for effective production of monoclonal antibodies.
Now, production of monoclonal antibodies by cell fusion technique have been established, and many workers have attempted and are still attempting producing new monoclonal antibodies which recognize cancer-related antigens and are useful for diagnosis and/or treatment of cancers.
Among numbers of monoclonal antibodies reported up to now, the monoclonal antibody developed by H. Koprowski et al., CA19-9 (1116NS19-9) is at present expected for practical use in the serum diagnosis of pancreatic cancer. However, this is insufficiently effective for diagnosis of other cancers including gastric cancer.
Generally, the production of monoclonal antibodies recognizing cancer-related antigens has hitherto been performed by administering cancer cells to an animal, for example, mouse or rat, which has the thymus, in other words, which is equipped with both B cells and T cells, to immunize the animal with the cancer cells, fusing antibody-producing cells obtained from the immunized animal with myeloma cells, selecting fused cells producing a desired antibody, cloning the fused cells, and culturing the cloned fused cell. Other method is not availabe nor has been reported.
The present inventors have studied monoclonal antibodies and new methods for production thereof. Now, we have found a monoclonal antibody which highly efficiently reacts with various cancers including gastric cancer, and a novel method for production of monclonal antibodies which is quite different from conventional methods.